Bell-shaped magnet



Patented Aug. 5, 1924.

lUNITE!) STI@ HERMANN STEINHART, 0F STUTTGART, GERMANY,

AKTIENGESELLSCHAFT, OF STUTTG" Moties assis-non ro .soscn r, enr naar.

BELL-SHAPED MAGNET.

Application tiled. Fletcher 13, 1922. Serial No. 594,403.

To all tol/wm t may concern.'

Be it known that I, HERMANN STEINHART, a citizen of Germany, residing atl Stuttgart, Germany, have invented certain new and useful Improvements in a Bell-Shaped Magnet, of which the following is a specification.

vThe bell-shaped magnet consists of straight profile bars of magnet-steel and of two yoke pieces located at the ends of said bars, the one yoke-piece connecting the bars magnetically, whereas the other serves merely to secure them in their proper relative position.

The known bell-shaped magnets composed in the just-mentioned manner have screws by which the yoke pieces are connected with the ends of the straight bars. Manufacturing such magnets is, however, difiicult and expensive because the hard material of the magnet bars can be worked only with ditliculty. Besides, the threads cut into the holes intended to receive the connecting screws warp easily when the bars are hardened, and it also occurs that said holes or bores cause cracks which render the respective bar or bars useless.

To obviate such and other drawbacks, the magnet bars and the yoke pieces are connected with each other, according to this invention, by outer cavities or recesses provided in the bars at their ends, and by bending the adjacent portions of yoke flanges into those cavities or recesses. There are now no threaded holes and no screws, and working the bars is materially facilitated and made cheaper. Besides, the waste is much smaller, because the chief cause for it, viz, the bores in the magnet bars, no more exists.

My invention is illustrated, by way of eX- ample, in the accompanying drawing, in which Figure l is a longitudinal section through a bell-shaped magnet constructed according to this invention and having no pole-shoes. Figure 2 is a transverse section in line A-B of Figure l. Figure 3 is a. longitudinal sectional view of a modified form of the invention having laminated pole shoes, and Fig-4 is a. longitudinal sectional view of another form of the invention having massive pole shoes.

Referring to Figures l and 2, a and o are two profiled bars consisting of magnet steel and being of the same length. Each bar has at both its ends an outer groove c, or d respectively, and at the one end of the magnet bars is a yoke c of soft iron and at the other end is a yoke g consisting' of not magnetizable material for instance brass. Both yo are flanged toward the bars, and the flangeparts adjacent to the grooves c and d are bent down into them, as illustrated in Figure l. The whole structure forms a bell-shaped magnet having its poles at d. The flange portions which lie between the two magnet bars are bent a little radially inwards (F ig. 2) whereby the magnets are prevented from moving circumferentially. rlhe structure is, thus, perfectly rigid.

As the yoke pieces consist of soft material, the other parts of the machine or apparatus may be atliired to them without manufacturing dimculties. The yoke piece e may serve as bearing for the armature shaft.

in the form of construction shown in F igure S the yoke g holds also a non-magnetic ring i to which laminated pole-shoes lo and 1n are affixed. The ring a' is firmly clamped in between the frontal end surfaces of the magnet bars and the yoke and is thus securely held in place without any special fastening' means.

The bell-shaped magnet illustrated in Figure 4.- is very similar to that shown in Figure 3, but the pole-shoes are massive and so shaped that they contact with the ends of the magnet. bars only as much as requisite for the proper guidance of the full magnetic fluir of the lines of force. The other portions of the pole-shoes are separated from the magnet bars by air gaps a, whereby a greater mean length of the magnet legs is obtained, as well as a better utilization of the whole magnet.

l claim:

vl. i bell-shaped magnet for magnetoelectric machines ant apparatus, comprising, in combination, straight prole bars consisting of magnet steel and having recesses at the outer surfaces of their ends, and yokes having fianges, of which the portions at the magnet bar ends are pressed down into said recesses.

2. A bell-shaped magnet for magnetoelectric machines and apparatus, comprising, in combination, straight profile bars consisting of magnet steel and having recesses at the outer surfaces of their ends; a yoke consisting of magnetic material and being flanged toward the bars and having the flange portions lying at the bar ends pressed down into the respective cavities; another Nvolte Consisting olf non-magnetic material and being also flanged and having also the flange portions lying at the respective har ends pressed down into the respective recesses.

3. A hell shaped magnet for magnetoelectrie machines and apparatus, Comprising, in oomhinatiom straight profile bars consisting of magnet steel and having recesses at the enter snritaces ot their ends, a yoke Consisting of magnetic material and being flanged toward the bars and having the lange portions lying at the har ends pressed down into the respective recesses; another yoke consisting ot non-magnetic material and being also 'flanged and having also the v[lange portions lying at the respective har ends pressed doivn into the respectivev recesses; a ring clamped in between said latter yoke and the respective frontal end surfaces o" the niagnet bars, and pole shoes aliixed to said ring.

in testimoniY whereof l have aliirled my signature in presence ot two witnesses.

HERB/isili@ iwlllllNl'li/tlll lie. s] TWitnesses 2 HELMA PriNnnn, Fano 3V. SPITZ. 

